1. Field of the Invention
The present invention relates to semiconductor manufacturing, and in particular, to semiconductor die sorting.
2. Related Art
One of the steps used during manufacturing of semiconductor dice is sorting die from a wafer or other platform. During a typical manufacturing process, the dice are first fabricated onto a semiconductor wafer, which is typically comprised primarily of silicon, although other materials such as gallium arsenide and indium phosphide are also sometimes used. Each semiconductor wafer has a plurality of integrated circuit semiconductor dice and/or circuitry, arranged in rows and columns with the periphery of each integrated circuit being substantially rectangular in shape, the integrated circuits of the semiconductor die being formed through a combination of deposition, etching, and photo-lithographic techniques. The inactive silicon backsides of the wafers are typically thinned (i.e., have their cross sections reduced) by a mechanical and/or chemical grinding process, and the wafers sawed into substantially rectangular-shaped discrete integrated circuit semiconductor dice.
During the fabrication and/or sawing process, individual dice may be damaged or defective. To prevent shipment or usage of defective dice, each of the dice is tested or probed to determine the level of functionality of the die. The die sorting, which can be in-situ with the testing, sorts the die identified from the testing step. For example, testing may identify a die as “good” or “bad”, depending on the level of performance required by the die. Identification typically involves marking bad dies with a probe, ink mark, or other identifier. The dice are then sorted accordingly, such as placement into appropriate carriers so that the same types of dice, functionally, are grouped together. Depending on the type of output desired, different carriers can be used to hold the sorted die, depending on the requirements of the end customer. Some current output carriers include waffle packs, GEL-PAK die carriers, tape or adhesive mounted frames, and JEDEC trays.
The die sorting is usually performed with an equipment called a die sorter. The die sorter typically receives a wafer containing the dice to be sorted. Individual die are then selected from the wafer and placed into an output carrier. However, because the output carriers are different (e.g., different sizes, die trays, and/or handling procedures), the die sorter needs to be flexible to accommodate the different output carriers. Thus, die sorters should be able to be changed (e.g., mechanically and/or to software) each time a different output carrier is used to adjust for those differences. For example, the die sorter may first sort the dice onto a tape. If the die sorter is to next sort the dice onto a waffle pack, a different handler for the output carrier will be needed, as well as possible changes to the software and handling procedure. This need to change the die sorter results in added time and costs, as well as lower throughput due to increased downtime, for the overall die sorting processes.
Accordingly, there is a need for an improved die sorter that overcomes the deficiencies in the prior art as discussed above.